import { bytesToHex, bytesToWords, endian, Md5Sha1Options, wordsToBytes } from "./crypt";
import { bin, utf8 } from "../charenc";

declare const Buffer;


function FF(a, b, c, d, x, s, t) {
	const n = a + (b & c | ~b & d) + (x >>> 0) + t;
	return ((n << s) | (n >>> (32 - s))) + b;
}

function GG(a, b, c, d, x, s, t) {
	const n = a + (b & d | c & ~d) + (x >>> 0) + t;
	return ((n << s) | (n >>> (32 - s))) + b;
}

function HH(a, b, c, d, x, s, t) {
	const n = a + (b ^ c ^ d) + (x >>> 0) + t;
	return ((n << s) | (n >>> (32 - s))) + b;
}

function II(a, b, c, d, x, s, t) {
	const n = a + (c ^ (b | ~d)) + (x >>> 0) + t;
	return ((n << s) | (n >>> (32 - s))) + b;
}

function _md5(message, options: Md5Sha1Options) {
	let i;
// Convert to byte array
	if (message.constructor == String)
		if (options && options.encoding === 'binary')
			message = bin.stringToBytes(message);
		else
			message = utf8.stringToBytes(message);
	else if (typeof Buffer !== 'undefined' && typeof Buffer.isBuffer == 'function' && Buffer.isBuffer(message))
		message = Array.prototype.slice.call(message, 0);
	else if (!Array.isArray(message))
		message = message.toString();
	// else, assume byte array already

	const m = bytesToWords(message),
		l = message.length * 8;
	let a = 1732584193,
		b = -271733879,
		c = -1732584194,
		d = 271733878;

	// Swap endian
	for (i = 0; i < m.length; i++) {
		m[i] = ((m[i] << 8) | (m[i] >>> 24)) & 0x00FF00FF |
			((m[i] << 24) | (m[i] >>> 8)) & 0xFF00FF00;
	}

	// Padding
	m[l >>> 5] |= 0x80 << (l % 32);
	m[(((l + 64) >>> 9) << 4) + 14] = l;

	for (i = 0; i < m.length; i += 16) {

		const aa = a, bb = b, cc = c, dd = d;

		a = FF(a, b, c, d, m[i + 0], 7, -680876936);
		d = FF(d, a, b, c, m[i + 1], 12, -389564586);
		c = FF(c, d, a, b, m[i + 2], 17, 606105819);
		b = FF(b, c, d, a, m[i + 3], 22, -1044525330);
		a = FF(a, b, c, d, m[i + 4], 7, -176418897);
		d = FF(d, a, b, c, m[i + 5], 12, 1200080426);
		c = FF(c, d, a, b, m[i + 6], 17, -1473231341);
		b = FF(b, c, d, a, m[i + 7], 22, -45705983);
		a = FF(a, b, c, d, m[i + 8], 7, 1770035416);
		d = FF(d, a, b, c, m[i + 9], 12, -1958414417);
		c = FF(c, d, a, b, m[i + 10], 17, -42063);
		b = FF(b, c, d, a, m[i + 11], 22, -1990404162);
		a = FF(a, b, c, d, m[i + 12], 7, 1804603682);
		d = FF(d, a, b, c, m[i + 13], 12, -40341101);
		c = FF(c, d, a, b, m[i + 14], 17, -1502002290);
		b = FF(b, c, d, a, m[i + 15], 22, 1236535329);

		a = GG(a, b, c, d, m[i + 1], 5, -165796510);
		d = GG(d, a, b, c, m[i + 6], 9, -1069501632);
		c = GG(c, d, a, b, m[i + 11], 14, 643717713);
		b = GG(b, c, d, a, m[i + 0], 20, -373897302);
		a = GG(a, b, c, d, m[i + 5], 5, -701558691);
		d = GG(d, a, b, c, m[i + 10], 9, 38016083);
		c = GG(c, d, a, b, m[i + 15], 14, -660478335);
		b = GG(b, c, d, a, m[i + 4], 20, -405537848);
		a = GG(a, b, c, d, m[i + 9], 5, 568446438);
		d = GG(d, a, b, c, m[i + 14], 9, -1019803690);
		c = GG(c, d, a, b, m[i + 3], 14, -187363961);
		b = GG(b, c, d, a, m[i + 8], 20, 1163531501);
		a = GG(a, b, c, d, m[i + 13], 5, -1444681467);
		d = GG(d, a, b, c, m[i + 2], 9, -51403784);
		c = GG(c, d, a, b, m[i + 7], 14, 1735328473);
		b = GG(b, c, d, a, m[i + 12], 20, -1926607734);

		a = HH(a, b, c, d, m[i + 5], 4, -378558);
		d = HH(d, a, b, c, m[i + 8], 11, -2022574463);
		c = HH(c, d, a, b, m[i + 11], 16, 1839030562);
		b = HH(b, c, d, a, m[i + 14], 23, -35309556);
		a = HH(a, b, c, d, m[i + 1], 4, -1530992060);
		d = HH(d, a, b, c, m[i + 4], 11, 1272893353);
		c = HH(c, d, a, b, m[i + 7], 16, -155497632);
		b = HH(b, c, d, a, m[i + 10], 23, -1094730640);
		a = HH(a, b, c, d, m[i + 13], 4, 681279174);
		d = HH(d, a, b, c, m[i + 0], 11, -358537222);
		c = HH(c, d, a, b, m[i + 3], 16, -722521979);
		b = HH(b, c, d, a, m[i + 6], 23, 76029189);
		a = HH(a, b, c, d, m[i + 9], 4, -640364487);
		d = HH(d, a, b, c, m[i + 12], 11, -421815835);
		c = HH(c, d, a, b, m[i + 15], 16, 530742520);
		b = HH(b, c, d, a, m[i + 2], 23, -995338651);

		a = II(a, b, c, d, m[i + 0], 6, -198630844);
		d = II(d, a, b, c, m[i + 7], 10, 1126891415);
		c = II(c, d, a, b, m[i + 14], 15, -1416354905);
		b = II(b, c, d, a, m[i + 5], 21, -57434055);
		a = II(a, b, c, d, m[i + 12], 6, 1700485571);
		d = II(d, a, b, c, m[i + 3], 10, -1894986606);
		c = II(c, d, a, b, m[i + 10], 15, -1051523);
		b = II(b, c, d, a, m[i + 1], 21, -2054922799);
		a = II(a, b, c, d, m[i + 8], 6, 1873313359);
		d = II(d, a, b, c, m[i + 15], 10, -30611744);
		c = II(c, d, a, b, m[i + 6], 15, -1560198380);
		b = II(b, c, d, a, m[i + 13], 21, 1309151649);
		a = II(a, b, c, d, m[i + 4], 6, -145523070);
		d = II(d, a, b, c, m[i + 11], 10, -1120210379);
		c = II(c, d, a, b, m[i + 2], 15, 718787259);
		b = II(b, c, d, a, m[i + 9], 21, -343485551);

		a = (a + aa) >>> 0;
		b = (b + bb) >>> 0;
		c = (c + cc) >>> 0;
		d = (d + dd) >>> 0;
	}

	return endian([a, b, c, d]);
}

export function md5(content: string | number): string {
	return bytesToHex(wordsToBytes(_md5(content + "", undefined)));
}
